Pain is a major public health issue that affects 1 in 5 Americans. After surgery, 70-80% of patients experience moderate to severe pain despite "state of the art" treatment with opioids and other drugs. Lecithin and phosphatidylcholine are nutritional supplements that are widely marketed to increase choline intake in humans. There is considerable evidence from animal models that choline supplementation has pain-relieving properties and can reduce inflammatory and postoperative pain. Choline is thought to have analgesic properties in animals by activating a7 nicotinic acetylcholine receptors in neurons and/or inflammatory cells. We propose a pilot clinical study to determine whether supplementation with lecithin and phosphatidylcholine to increase plasma choline concentrations before gynecological surgery will decrease post-operative pain. We will conduct a linked pharmacokinetic/ pharmacodynamic trial with the primary outcome variable of reported pain score after surgery. In this placebo-controlled double-blind study all patients will receive the optimal postoperative pain regimen with morphine via PCA. We will assess whether choline supplementation affects patients'use of pain medication and satisfaction with pain relief. Furthermore, we will conduct an exploratory analysis of subject macrophages for a7 receptor expression level and activity in subject macrophages. We will determine whether heterogeneity in a7 nicotinic receptors is predictive of intra-individual variation in choline efficacy. PUBLIC HEALTH RELEVANCE: This is a pilot pharmacokinetic/pharmacodynamic study to determine whether nutritional supplementation with lecithin increases plasma choline concentration and decreases pain after surgery. In an exploratory analysis we will determine whether supplementation reduces the activity of subject macrophages through an alpha 7 nicotinic receptor dependent pathway.